Banana weevil (Cosmopolites sordidus
Germar, Coleoptera, Curculionidae)
The
larva of the banana weevil, also known as the banana beetle and banana borer,
bore into the corm of the banana plant. The female weevil bites a small hole in
the corm, lays a single egg and continues this activity on other plants
throughout the year. The larvae bore into the corm, where they feed, making a
tunnel and pupate in the same tunnel. The adults, on emergence, remain in the
soil for sometime, feeding on the underground parts of the plants.
Damage
symptoms :This insect attacks
only members of the genus Musa. The damage done by the weevil is through
the destruction of the corm tissue. The seedlings/ sucker are killed as
a result of the borer attack when the larvae approach the growing point. The
tunnelled corms sometimes break out, since the weevils do not attack roots,
they do not cause toppling over.
Cultural
control : Destroy the sheltering
and feeding places of the adult weevils. The pseudo stems, from which the
bunches have been cut, are chopped up and scattered in the plantation so that
they rot quickly. Also, the pseudo stems should be cut close to the ground and
the infested suckers should not be used for planting.
Chemical
control: The suckers should be
dipped in 0.1% chlorpyriphos emulsion before planting.In case of attack, spray
dimethoate 30 EC @ 2 ml/l of water, around the base of the plants or clumps.